Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Plastic Embedding”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 505 records · Page 28Linked to original sources
PubMed2005

The past, present, and future of bone morphometry: its contribution to an improved understanding of bone biology.

It was not until the 1950s that a better paradigm for bone biology evolved, which led to the birth of bone histomorphometry. Two clinicians, Harold Frost (1958-1964) and Lent Johnson (1964), were responsible for the paradigm stating that the primary function of bone is mechanical load bearing with subsidiary function to participate in plasma calcium homeostasis to support hematopoesis. Dynamic bone histomorphometry was born when Milch et al. (1958) discovered bone localization of tetracycline and Frost generated the methodology to study tetracycline-based dynamic histological analysis of cortical bone remodeling (1961-1965). Dynamic bone histomorphometry did not blossom until Frost, while a Sun Valley Workshop participant, developed it to address trabecular bone dynamics. The combination of Arnold (1948) producing thin sections of plastic-embedded undecalcified bone and Frost's (1977-1983) modification of dynamic cortical bone histology for cancellous bone made it possible to study tetracycline-based dynamic histomorphometry of cancellous bone. It led to the better understanding of basic metabolic unit (BMU) remodelling and to Frost's mechanostat hypothesis, and characterized the rat model to accelerate the development of several drugs in the treatment of bone diseases. Currently, dynamic bone histomorphometry has contributed to studies in bone's mechanical usage windows, mechanical usage setpoint hypothesis, muscle-bone relations, marrow-bone relations, the Utah paradigm of musculoskeletal physiology, apoptosis, genetics (transgenic mice) and bone structure, bone quality, the lacunocanalicular network and bone modelling, and remodeling hypothesis, osteocyte role as mechanosensory, chemosensory, and regulatory in bone maintenance, targeted and untargeted remodeling, the role of permissive agents, etc., items in bone biology expounded briefly by Lent Johnson (1965) and continuously by Harold Frost at the Sun Valley Workshop (1965-2003). Finally, "What's next?" covers how to improve and perpetuate the employing of qualitative histomorphometry in research opportunities in hard tissue research.

Animals↗
PubMed1998

Hepatic steatosis in liver transplant donors: common feature of donor population?

Fatty change in donor livers is a risk factor for poor function after orthotopic liver transplantation. Various prevalences of steatosis have been reported in time 0 biopsies. The aim of this research was to determine, in a longitudinal study, the degree (percent of hepatocytes involved) and type (size of vacuoles) of fatty change shown by various histologic techniques. Four staining methods were used on sections from three liver wedge biopsies--at liver procurement, at the back-table, and after reperfusion--from 83 consecutive donor livers. Results in Sudan III-stained (SS) sections showed the greatest sensitivity (87.1%), negative predictive value (91.8%), and agreement rate (k = 0.77) when compared with results in thin (1 micron) plastic-embedded toluidine blue-stained (TBS) sections. High-grade steatosis (> 30% steatotic hepatocytes) was identified in 49.4% of SS sections, 46.9% of TBS sections, 38.5% of frozen hematoxylin-eosin (H&E)-stained sections, and 20.7% of deparaffinated H&E-stained sections. Microscopic observations disclosed two types of steatotic pattern: (1) A predominantly small-droplet lipid vacuolzation (high-grade microsteatosis), similar to the steatosis associated with Reye syndrome, was seen in 29% of SS sections and 25% of TBS sections--approximately one-fourth of grafts; and (2) a combined pattern of large and small fat drops (high-grade macromicrosteatosis) was seen in 20% of SS sections and 22% of TBS sections. We concluded that moderate to severe steatosis is a frequent finding in donor livers. The difficulty in detecting lipidic microvacuoles in H&E-stained sections may be the reason for underestimating the grade of fatty change or even for diagnosing as normal some biopsies with high-grade microsteatosis.

Adolescent↗
PubMed2005

Potential of P40 plastination for morphometric hip measurements.

Total hip replacement has become one of the most successful surgical operations over the past 25 years. The duration of a total hip prosthesis depends on primary stability, and many studies have tried precisely to evaluate hip joint morphology to obtain excellent contact between bone and prosthetic component. This study performed a morphometric analysis of the human hip joint using, for the first time, the P40 plastination procedure. We cut 42 hip joint compounds into slices 3 mm thick; for exact distance measuring the sections were scanned into the computer. The following mean measurements for hip geometry were obtained: vertical diameter of acetabulum 4.894+/-0.274 cm, depth of acetabulum 1.643+/-0.245 cm, femoral head radius 2.268+/-0.149 cm, femoral neck length 4.3670+/-0.528 cm, acetabular perimeter 6.711+/-0.434 cm, vertical diameter of labrum acetabulare 4.759+/-0.476 cm, depth of labrum acetabulare 2.599+/-0.395 cm, sum of femoral head and neck lengths 6.759+/-0.550 cm, hip axis length 11.859+/-1.007 cm, femoral neck axis length 10.12+/-0.555 cm, and femoral neck diameter 3.349+/-0.276 cm. All of these data reveal a significant gender difference. Our aim was to indicate an unconventional and new method of gaining morphometric hip data by using plastination.

Acetabulum↗
PubMed1995

[Morphometry of megakaryocytes for supporting the histologic diagnosis of chronic myeloproliferative diseases].

Morphometric analysis of sections of biopsy specimens from patients with chronic myeloproliferative disorders (CMPD) can complement the individual histological diagnosis and help to distinguish the four groups of CMPD. A total of 130 diagnostic biopsies from 29 cases of chronic myelocytic leukemia (CML.CT), 26 cases of (CML.MI), 28 of essential thrombocythemia (PTH), 26 cases of chronic megakaryocytic granulocytic myelosis (CMGM), and 21 of polycythemia vera (P. vera), and 30 from healthy control persons were evaluated morphometrically in sections of undecalcified plastic-embedded core biopsies. Clear distinctions were revealed in size of megakaryocytes, nuclear lobulation, clustering, and the nuclear size and shape of megakaryocytes. Nuclear size and cellular size were significantly less in CML (range of means of cellular size: 220-360 microns2) than in the other three Ph1-negative groups (range of means: 480-750 microns2). Nuclear lobulation was more distinct in PTH than in P. vera, and especially in CMGM. Clustering of megakaryocytes was more than twice as frequent in CMGM (8.0-10.5%) as in any of the other three groups (0.1-7.0%). Naked nuclei were more numerous in all groups of CMPD. The main topic of the study is the different size of megakaryocytes in the four main groups of CMPE, allowing a distinction between small-megakaryocytic Ph1-positive CML and large-megakaryocytic Ph1-negative forms of CMPD.

Biopsy↗
PubMed1997

Rodent pancreatic islet cells contain the calcium-binding proteins calcineurin and calretinin.

Calcium is known to be of critical importance for hormone secretion in the insulin-producing B-cells of the endocrine, pancreas. Calcium-mediated intracellular signal transduction and the regulation of the concentration of free calcium in B-cells probably involve calcium-binding proteins. In the present study, we have investigated the expression of the calcium/calmodulin-dependent phosphatase, calcineurin, and the EF-hand calcium-binding protein, calretinin, in pancreata of hamsters, gerbils, and rats by immunocytochemistry. Immunocytochemical investigations of serial semithin sections of plastic-embedded pancreata revealed that calcineurin and calretinin were constantly present in islet cells of all three species. In addition to B-cells, these proteins could also be detected in glucagon (A-), somatostatin (D-), and pancreatic polypeptide (PP-) cells. Non-B-cells, especially glucagon-producing A-cells, often exhibited a significantly higher degree of immunoreactivity for both calcium-binding proteins than B-cells. Thus, calcineurin and calretinin may play distinct roles in the regulation of calcium-dependent secretory activities of the different pancreatic endocrine cell types.

Animals↗
PubMed2001

The juxtaglomerular apparatus in young type-1 diabetic patients with microalbuminuria. Effect of antihypertensive treatment.

BACKGROUND: Our goal was to investigate the effect of antihypertensive drugs on the juxtaglomerular apparatus (JGA) in young type-1 diabetic patients with microalbuminuria. METHODS: Twelve patients were allocated to treatment with either an angiotensin-converting enzyme inhibitor (group 1, six subjects) or a beta-receptor blocker (group 2, six subjects). A comparable group of nine patients without antihypertensive treatment provided reference values (group 3, nine subjects). Renal biopsies were taken at baseline and after a median of 40 months (groups 1 and 2) and 30 months (group 3). Using light microscopy with 1microm serial sections of the plastic-embedded biopsies, volumes of the JGA and glomerulus and areas of the macula densa and lumina of the afferent and efferent arterioles were obtained. RESULTS: A significant decrease of the volume of the JGA (P=0.026) and of the volume of the JGA relative to that of its corresponding glomerulus (P=0.0005) was noted in the reference group only. Negative correlations existed between the increase in the luminal area of the afferent arteriole and mean diastolic blood pressure in the study period in group 1 (P=0.024) and group 2 (P=0.032). CONCLUSIONS: Our results showed that a decrease in the size of the JGA is offset by antihypertensives. The negative correlation between the change in the luminal area of the afferent arteriole and mean diastolic blood pressure in groups 1 and 2 suggest that renal protection in antihypertensive treatment may be through a better constriction of the afferent arteriole protecting the glomerulus from systemic blood pressure.

Adolescent↗
PubMed2003

Lateral wall histopathology and endocochlear potential in the noise-damaged mouse cochlea.

Noise exposure damages the stria and spiral ligament and may contribute to noise-induced threshold shift by altering the endocochlear potential (EP). The aim of this study was to correlate lateral wall histopathology with changes in EP and ABR thresholds. CBA/CaJ mice were exposed to octave band (8-16 kHz) noise for 2 h at intensities ranging from 94 to 116 dB SPL and evaluated 0 h to 8 weeks postexposure. EP in control mice averaged 86 and 101 mV in apical and basal turns, respectively. The 94 dB exposures caused a 40 dB temporary threshold shift (TTS), and there was with no corresponding change in EP. The 112 and 116 dB exposures caused >60 dB threshold shifts at 24 h, and EP was transiently decreased, e.g., to 21 and 27 mV in apical and basal turns after 116 dB. By 1 week postexposure, EP returned to control values in all exposure groups, although those exposed to 112 or 116 dB showed large permanent threshold shifts (PTS). Cochleas were plastic-embedded and serial-sectioned for light microscopic and ultrastructural analysis. Acute changes included degeneration of type II fibrocytes of the spiral ligament and strial edema. The strial swelling peaked at 24 h when significant EP recovery, had taken place, suggesting that these changes reflect compensatory volume changes. In the chronic state, massive loss of type II fibrocytes and degeneration of strial intermediate and marginal cells was observed with drastic reduction in membrane surface area. The results suggest that EP shifts do not occur with TTS and also do not add significantly to PTS in the steady state. However, EP loss could contribute to acute threshold shifts that resolve to a PTS. EP recovery despite significant strial degeneration may be partly due to decreased transduction current caused by hair cell damage.

Animals↗
PubMed2002

Age-related blood flow and capillary changes in the rat utricular macula: a quantitative stereological and microsphere study.

Vascular change may contribute to age-related vestibular dysfunction. Previously, we reported a significant age-related decrease in blood flow (BF) and mean capillary diameter (D(cap)) in the rat posterior canal crista. The purpose of this study was to examine an otolith organ, the utricle, for similar changes. Old male Fischer 344 rats (O; 28-31 mos) were anesthetized, and the left cardiac ventricle was transcutaneously injected with radioactive microspheres to determine BF. The temporal bones were removed, fixed, and decalcified. The utricles were dissected free and placed into a gamma counter with the reference samples. The specimens were then plastic embedded and serially sectioned at 1 microm according to the vertical section technique. Microsphere surface counts were made and neuroepithelial BF calculated. A systematic random set of sections was sampled and analyzed using stereological techniques for estimates of D(cap), capillary surface area/unit volume (S(v,cap)), capillary length/ unit volume (L(v,cap)), and volume of utricular neuroepithelium (V(ut)). Using these data, total capillary surface (S(cap)) and total length (L(cap)) were calculated. Statistical comparisons were made with data from our previous study of young animals (Y; 3-6 mos). Results indicate a significant age-related decrease in BF (Y = 0.125 microL/min, O = 0.062 microL/min; P = 0.003), D(cap) (Y = 5.95 micro, O = 4.57 microm; P = 0.0002), S(vcap) (Y = 12.33 mm2/mm3, = 9.87 mm2/mm3, P = 0.016), S(cap) (Y = 0.178 mm2, O = 0.129 mm2; p = 0.01), and V(ut) (Y = 0.014 mm3, O = 0.013 mm3; P = 0.04) with no significant change in L(v,cap) (Y = 655 mm/mm3, O = 686 mm/mm3, P = 0.41) or L(cap) (Y = 9.47 mm, O = 8.96 mm; P = 0.49). These age-related vascular changes are likely to have a significant impact on utricular physiological and thus, dysequilibrium.

Acoustic Maculae↗
PubMed1981

Stumbler, a new mutant mouse with cerebellar disease.

A new mutant mouse named Stumbler (stu) displays clinical features suggesting a cerebellar lesion. The main light microscopic findings, based on a Golgi technique and on sections of plastic embedded material, are that Purkinje cells in the mutant cerebellum have small dendritic arborizations and exhibit immature spines on their somata. Purkinje cells also contain an increased number of mitochondrial profiles both in cell bodies and in swellings on dendrites.

Animals↗
PubMed1987

Opioid receptors in rat neostriatum: radioautographic distribution at the electron microscopic level.

The distribution of mu-opioid receptors, selectively labeled in vitro with a monoiodinated Met-enkephalin analog [( 125I]FK 33-824), was analyzed by light and electron microscopic radioautography in sections from the neostriatum of the rat. In the light microscope, patches of high receptor densities were detected amidst a moderately labeled matrix. The number of silver grains, as counted in 1-micron thick plastic-embedded sections, was 3 times greater inside the patches than in the intervening matrix. In both compartments, the proportion of labeled binding sites associated with the neuropil was significantly higher (greater than 70%) than that associated with nerve cell bodies or myelinated fascicles. Quantitative analyses of electron microscopic radioautographs revealed that the majority of silver grains corresponding to specifically bound [125I]FK molecules originated from radioactive sources associated with apposed neuronal membranes. Of the total number of specific binding sites, 53% was associated with axodendritic, 18% with axoaxonic and 3% with axosomatic interfaces. The occurrence of multiple labeled foci along the plasma membrane of certain perikarya and dendrites suggested that some of the binding sites might be associated with somato/dendritic elements. The high incidence of labeling along axoaxonic interfaces indicated that others were linked to the membrane of axons and/or axon terminals. A major finding of the present study was that only a small proportion of specific FK binding sites (7% of total) was associated with synaptic junctions. Labeled synapses were primarily of the asymmetric type and were found predominantly on dendritic branches and spines. A few were observed on nerve cell bodies. Labeled symmetric synapses were rare and encountered exclusively on dendritic branches. The high frequency with which specifically labeled binding sites were found to be associated with neuronal interfaces involving axonal processes strongly suggests that even if non-junctional these binding sites correspond to functional receptors. Whether these receptors are activated by endogenous ligand molecules released by the labeled terminals themselves or from terminals located at a distance from the labeled interfaces remains to be determined.

Animals↗
PubMed1988

Selective neuronal destruction by Ricinus communis agglutinin I and its use for the quantitative determination of sciatic nerve dorsal root ganglion cell numbers.

The selectivity of the neurotoxic lesion of Ricinus communis agglutinin I (RCAI) in rat dorsal root ganglia was examined. RCAI was injected in the sural nerve on one side. Two weeks later, the injected nerve, as well as the ipsilateral peroneal nerve, were examined in 1-micron-thick plastic embedded sections in the light microscope. The injected nerves showed a complete or almost complete Wallerian-like degeneration of myelinated fibers, but there were no signs of fiber damage in the uninjected nerves, which to a large extent originate in the same ganglia as the injected ones. We conclude that RCAI does not diffuse into and destroy ganglion cells adjacent to those that have transported the substance. We then used this selectivity in the effect of RCAI to determine indirectly the relative number of neurons in dorsal root ganglia L4-L6 which contribute to the sciatic nerve. Three weeks after unilateral injections of RCAI in the sciatic nerve, the L4-L6 dorsal root ganglion cells were counted bilaterally. On average, relative neuronal numbers between injected and uninjected sides were 0.36, 0.15 and 0.64 for L4, L5 and L6 respectively. From these data we conclude that the sciatic nerve receives on average of 64%, 85% and 36%, respectively of its sensory contribution from these ganglia.

Animals↗
PubMed1987

Quantitative analysis of germ cells and Leydig cells in rat made infertile with gossypol.

This study utilized improved methods of fixation and plastic embedding to quantitatively evaluate the effects of gossypol on germ cells and Leydig cells in testes of rats made infertile with gossypol. Rats were fed by gavage with 10, 20 or 30 mg/kg per day of gossypol for 9 weeks; control animals received the vehicle alone. Numbers of A spermatogonia, preleptotene and pachytene spermatocytes, and step 7 or 8 spermatids per Sertoli cell were counted in stages VII-VIII of the cycle of the seminiferous epithelium. Although high doses (30 mg/kg) of gossypol produced a significant decrease in the relative number of germ cells compared with vehicle-treated controls, no significant deviation in the relative number of germ cells was noted between controls and rats made infertile with 10 or 20 mg/kg/day of gossypol. Stereologic techniques were used to assess the changes in the Leydig cells. No significant deviation in the Leydig cell morphology, cell number, or cell volume was noted as a result of gossypol treatment at the dose levels employed. It appears that germ cell depletion, such as that caused by high doses of gossypol, is not mediated by a change in Leydig cell function. The present report emphasizes the importance of studies to determine the minimal effective doses for gossypol's antifertility activity in animal models as well as in man.

Animals↗
PubMed1985

Shaping and bending of the avian neuroepithelium: morphometric analyses.

Changes in the size and shape of the neuroepithelium were measured from serial transverse sections of 30 plastic-embedded chick embryos at stages 4-11. The neural plate folds into a neural tube during this period. Changes in volume, length, apical and basal widths, apical and basal surface areas, and thickness of the neuroepithelium were measured and correlated with the amount of folding that had occurred. These measurements were made to provide data for comparison with those available from other systems, to gain insight into the mechanisms of shaping and bending of the neuroepithelium, and to obtain normal parameters for eventual comparison with those obtained from embryos with induced neural tube defects. During stages 4-11, the volume, length, apical and basal surface areas, and lateral thickness of the neuroepithelium increase, whereas apical and basal widths and median thickness of the neuroepithelium decrease. Models are presented to demonstrate the effects of possible changes in neuroepithelial cell number, position, and size on the shaping of the neural plate.

Animals↗
PubMed1984

Fasciola hepatica and Schistosoma mansoni: immunofluorescent antigen localization and cross-reactivity.

In an attempt to identify the tissue sources of biochemically purified antigenic fractions of Fasciola hepatica and Schistosoma mansoni, antisera were tested against plastic-embedded sections of worms of various ages by an indirect fluorescent-antibody-labeling technique. Antibodies prepared against antigens purified by chromatography of F. hepatica whole worm extract through concanavalin A-Sepharose 4B labeled the parenchyma and tegument of adult F. hepatica strongly while antibodies developed against antigens purified by antibody-affinity chromatography against antibodies of S. mansoni labeled only the parenchyma. Antigens common to these two groups clearly originated from F. hepatica parenchyma. Certain of these common antigens are known to provide significant protection in mice to challenge with S. mansoni cercariae, and in the present study antisera against F. hepatica extracts cross-labeled S. mansoni adult male parenchyma. Reciprocal cross-reactions between antisera against S. mansoni and the parenchyma of adult F. hepatica were also noted. FhFIIb, an extract of F. hepatica which Tailliez described as not cross-reacting with S. mansoni, was found to contain no F. hepatica parenchymal antigens. Antigenic fractions of F. hepatica and S. mansoni collected from the surface of worms after incubation in nonionic detergent were unexpectedly found to contain much parenchymal antigen, suggesting leakage of internal components into the supernatant during preparation. Antisera to F. hepatica developed during a natural infection in rabbits labeled tegumental components and gut strongly but did not react with parenchymal tissue. Antisera against extracts of adult schistosomes labeled the parenchyma of male worms and the glycocalyx of the cercarial tegument, indicating the presence of common antigens in the adult and the cercarial stage. Reciprocal reactions between anticercarial sera and adult sections provided further evidence of shared antigenicity. Antisera against S. mansoni egg antigens strongly labeled sections of eggs in liver tissue and cross-reacted with cercarial glycocalyx, indicating the existence of common antigens between these two stages. The antisera also cross-reacted with what appeared to be non-membrane-bound protein in the tegument of F. hepatica. The soluble egg antigen extract shared antigenicity with the parenchyma of both S. mansoni and F. hepatica but circumoval precipitin had no cross-reactivity with this tissue. Thus S. mansoni eggs contain nondiffusable components sharing antigenic specificity with adult parenchymal tissue.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Isolation of human splenic macrophages and lymphocytes by countercurrent centrifugal elutriation.

Certain tissues, such as the spleen, are rich sources of mononuclear phagocytes (MP); however, separating the phagocytes from tissues and removing the contaminating cells have been difficult. We report here a method for the extraction and purification of human splenic MP that employs gentle homogenization of splenic fragments with a Tenbroeck tissue homogenizer, controlled digestion with purified collagenase to free MP from splenic stroma, incubation with DNase to dissociate cell clumps and purification by countercurrent centrifugal elutriation (CCE). With homogenization and enzymatic digestion most of the splenic nonspecific-esterase-positive cells are freed into suspension as determined by morphometric analysis of 2 micron sections from plastic embedded spleen stained for alpha-naphthyl butyrate esterase (ANB). Overall cell recovery after homogenization and enzyme treatment is 56 +/- 7%; no selective cell loss occurs as determined by differential cell counts at each purification step. CCE of up to 3 X 10(9) treated spleen cells results in recovery of 63 +/- 6% of the elutriated cells and separates nearly 50% of the recovered MP into enriched fractions. These MP are morphologically intact as determined by light and electron microscopy and are actively phagocytic. Highly purified (96%) autologous splenic lymphocytes are a useful by-product of this separation technique.

Cell Count↗
PubMed1989

The microvascular system of the optic nerve in control and enucleated rats.

The microvascular system of the optic nerve of the rat was examined morphometrically to determine the effect of enucleation of one eye at birth on the microvascular development in the contralateral optic nerve. For this purpose, two groups of rats were used: three were unilaterally enucleated on the day of birth and studied on postnatal Day 28; three littermates were used as controls. Using plastic embedded semithin sections, we analyzed various parameters and compared the results statistically. The average diameter of microvessels up to 7.5 microns was found to be 4.7 +/- 0.2 micron in controls and 5.3 +/- 0.5 micron in experimental rats. The density of microvessels expressed as the mean number of sectioned capillaries per tissue area was 137 +/- 25/mm2 in the control group and 169 +/- 32/mm2 in the experimental group. The intravascular volume fraction percentage (Vv), which represents the volume fraction of the capillary network per unit of optic nerve volume (mm3/mm3%), was 0.06% in the controls and 0.10% in the enucleated rats. Total length of capillaries per unit of volume (Lv) averaged 1050 +/- 112 and 2235 +/- 195 mm/mm3 in control and experimental groups, respectively. The internal capillary surface area available for metabolic exchange expressed per volume unit (Sv) was 15.5 +/- 2.1 and 37.2 +/- 2.8 mm2/mm3 in control and experimental groups, respectively. These results, together with the lack of ultrastructural modifications in the vascular walls of microvessels, suggest that these rearrangements of the capillary system in the enucleated group could be triggered by an increase in the optic nerve metabolism resulting from monocular vision.

Animals↗
PubMed1990

Combined conventional transmission, scanning, and high-voltage electron microscopy of the same blood vessel for the study of targeted inflammatory cells in blood-brain barrier inflammation.

The microvasculature of brains and spinal cords from mice subjected to chronic relapsing experimental autoimmune encephalomyelitis (CREAE) was studied using three different electron microscopic techniques. Blood vessels were initially examined by scanning electron microscopy. This allowed for the investigation of topographical changes of the luminal aspects of endothelial cells (ECs) and identification of targeted inflammatory cells (ICs) attached to the ECs. The same blood vessel areas with attached ICs examined by scanning electron microscopy were subsequently trimmed, processed for routine conventional transmission electron microscopy, and plastic embedded. Thin (80 nm) sections were cut and evaluated. Semithick (0.5-0.75 microns) serial sections of this material were examined by high-voltage electron microscopy. Data presented here described a useful technique for combining several ultrastructural techniques that permits simultaneous topographic and cross-sectional examination of selected regions of individual blood vessels or specifically targeted ICs.

Animals↗
PubMed1986

Macromolecular organization of bovine lens capsule.

Rabbit antisera to type IV collagen, laminin, entactin, heparan sulfate proteoglycan and fibronectin were used to localize these proteins in cross-sections of bovine anterior lens capsule. The antisera were exposed to (a) 10-micron frozen-thawed sections of formaldehyde-fixed tissue for examination in the light microscope by the indirect immunofluorescence method and (b) formaldehyde-fixed and L. R. White plastic-embedded thin sections for electron microscopic examination by the protein A-gold technique. The intensity of immunofluorescence was both uniform and strong throughout for type IV collagen, laminin and entactin, but patchy and weak for fibronectin. Electron microscopic immunolabeling with protein A-gold showed that all five components were distributed throughout the full thickness of the membrane, albeit the density of gold particles was not identical for all basement membrane proteins. In general, the number of particles per micron2 was greatest for type IV collagen and entactin, moderate for laminin and heparan sulfate proteoglycan and low for fibronectin. The ultrastructure of the lens capsule as examined by the electron microscope revealed a relatively uniform parallel alignment of filaments, thought to be collagenous. Since the distribution of the filaments corresponds well with the observed immunocytochemical pattern it is concluded that type IV collagen, laminin, entactin, heparan sulfate proteoglycan and fibronectin co-localize throughout the cross-section of the anterior lens capsule.

Animals↗